Based on data reviewed by a consensus conference convened by the American Academy of Dermatology Association to examine the relationship between sunlight, tanning booths and vitamin D, renowned medical experts agreed that increasing exposure to either natural or artificial ultraviolet (UV) light should not be recommended as a supplemental source of vitamin D. However, the conference experts noted that there is growing evidence demonstrating that many people in the U.S. – particularly older adults, women, and darker-skinned individuals – may have vitamin D levels below those necessary for optimum health.
Speaking today at the Academy’s Melanoma/Skin Cancer Detection and Prevention Month news conference, dermatologist Vincent A. DeLeo, M.D., associate professor of clinical dermatology, Columbia University, New York, N.Y., and chairman of the department of dermatology at both St. Luke’s Roosevelt and Beth Israel Hospital Centers, New York, N.Y., presented findings from the conference white paper published in the May 2005 issue of the Journal of the American Academy of Dermatology reviewing the data on sunlight, tanning booths and vitamin D.
“It is known that there is a high risk of developing skin cancer from repeated and intentional ultraviolet B exposure to boost vitamin D levels; the latter can be safely achieved by nutritional supplements,” said Dr. DeLeo. “Skin cancer is an epidemic in this country and recommending increased UV exposure with claims that sunlight somehow promotes good health is highly irresponsible.”
The benefits of vitamin D are well documented and include, most notably, improved bone health and fracture prevention, better muscle health and a reduced risk of falling in older individuals. While these benefits are particularly important for older adults who are at risk to developing osteoporosis, research suggests that this age group is most prone to vitamin D deficiencies and requires the highest recommended daily intake. Currently, the recommended intakes of vitamin D by age group are 200 International Units per day (IU/d) for young adults, 400 IU/d for those aged 51 to 70 years, and 600 IU/d for those over age 70. There is evidence however that these recommended levels are too low for optimum health. Without supplemental dosages of vitamin D, experts warn that older individuals are not getting enough of the nutrient they need through incidental sun exposure or foods.
“When people age, their skin becomes less equipped to process vitamin D absorption through incidental sun exposure,” said Dr. DeLeo. “Since their daily vitamin D requirements are so much higher than their younger counterparts, it is very important that they take vitamin D supplements and increase their intake of vitamin D enriched foods such as milk and other fortified dairy products, fortified orange juice and certain kinds of fish.”
Another population most at risk for vitamin D deficiency is darker-skinned individuals, whose increased melanin, the natural substance that gives skin its pigment, reduces the skin’s ability to photosynthesize vitamin D. Whereas lighter-skinned individuals will generate some vitamin D production from incidental sun exposure, those with darker-pigmented skin require longer exposure times to achieve a similar result. In addition, darker-skinned individuals as a whole also are more likely to be lactose intolerant and consume less milk – one of the main sources of vitamin D. Dr. DeLeo noted that this group may need to take nutritional supplements of vitamin D and consume other vitamin D enriched foods to ensure adequate vitamin D levels.
For those individuals who don’t fall into the two groups most at risk for vitamin D deficiency, experts still caution them against relying on intentional ultraviolet exposure for vitamin D production as some controversial studies would recommend. Photosynthesizing vitamin D through natural sunlight is maximized after 20 minutes of ultraviolet B (UVB) exposure, with extended sun exposure providing no additional benefit but instead increasing the likelihood of photodamage and skin cancer.